Cushioning device for drawing presses



Aug. 19, 1930. F. J. RODE 1,773,439

CUSHIONING DEVICE FOR DRAWING PRESSES Filed April 13, 1929 4 Sheets-Sfieet 1 Aug. 19, 1930. F. J. RODE CUSHIONING DEVICE FOR DRAWING PRESSES FiledApril 13, 1929 4 Sheets-Sheet 2 39 Via-i I Aug. 19, 1930. F. J. RODE 1,773,439

CUSHIONING DEVICE FOR DRAWING PRESSES Filed April 15, 1929 4 Sheets-Sheet 3 l l l I l I I Aug. 19, 1930. F. J. RODE ,77

CUSHIONING DEVICE FOR DRAWING PRESSES Filed April 15, 1929 4 Sheets-Sheet 4 vim- I I an 1 Patented Aug. 19, 1930 FREDRICH J. RODE, OF CHICAGO, ILLINOIS CUSHIONING DEVICE IFOR DRAWING PRESSES Application filed April 13,

This invention relates to improvements in cushioning devices 'particularly adapted, though not necessarily limited in its use, with sheet metal drawing presses.

In presses for drawing sheet metal and the like in which the material is shaped by means of co-operating dies, one of which is reciprocable toward and away from the other, the work is usually held by means of a work hold- I er or draw ring which co-operates with one of the dies, the work holder or draw ring being yieldingly resisted in its movement in one direction by means ofa fluid cushioning device through the medium of a pressurepad.

Heretofore the cushions generally comprise separate co-operating piston and cylinder elements, one of which elements is attached to a stationary part of the press and the other to the pressure pad, fluid being supplied to the cushion from a separate tank.

It is one of the objects of the present in-' vention to improve and simplify the cushionin g means and reduce to a minimum the number of parts and attachments necessary as Well-as dispense with a separate fluid supply tank and the separate cylinder and piston elements. v

To that end the cushioning means is formed as a unitary structure adapted to be applied to a press as such, a cylinder element being provided in which a plurality of pistons operate, the cylinder holdin a predetermined supply of fluid compressi le by the pistons for yieldingly resisting the movement of the pistons in one direction, with the result that a more compact arrangement will be provided than could be obtained by the use of a plurality of different or separate cylinder and piston units, and with the further result that aseparate fluid supply tank will also be dispensed with.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in. the features" of novelty in substantially the construction, combination and arrangement of the several parts hereinafter more'fully described and claimed and shown in the accompanying drawings illustrating this invention, and in which-- 1929. Serial No. 354,307.

Figure 1 is a view in front elevation, partly broken away and with parts omitted, of a sheet metal drawing press having a cushioning device constructed in accordance with the principles of this invention applied thereto.

Figure 2 is a vertical sectional View taken on line 2-2, Figure 1.

Figure 3 is. a view similar to Figure 1 of another form of the invention.

Figure 4 is a verticalsectional view taken online 4 4, Figure 3.

Referring more particularly to the drawings the numeral designates the bed of a press having an opening 11 therein, over which a bed or bolster Supported by the plate 12 is a die 13 with which a reciprocating die 14 mounted upon a movable ram 15 co-operates. The ram is adapted to slide upon the uprights 16 of the press preferably by means of links 17 'connected with the ram and also with the shaft 18, which latter is rotated by means of any suitable source of power (not shown). Cooperating with the die 13 and encompassing the same is a draw ring or work holder 19 l -which is supported by means of pins 20 that pass loosely through the bed or bolster plate 12, and the pins 20 engage and rest upon a pressure pad 21 arranged beneath the bed plate 12. I

' All of the above referred to parts are of the ordinary and Well known construction.

In the form of the invention shown in Figplate 12 is arranged ures 1 and 2, there is provided a support 22 which is arranged below the bed or bolster plate 12 at any suitable point and is supported or heldin position in any suitable manner such as by means of hanger rods 23, the ends 'of'which pass through the support 22 and have collars or nuts 24. connected to said end. The other end of the'rods or hangers 23', any number of which may be provid ed, pass through a suitable stationary portion 25 of the press, preferably a portion of the bed of the press, and nuts or collars 26 are secured to the ends of the rods 23.

This support 24 constitutes one end of a cylinder or chambered member 27 which may be of any desired size-and the cylinder is secured to the support 22 by means of suitable fastening devices 28.

A partition 29 is referably provided in the cylinder 27 to divi e the same into chambers, having communication with each other preferablyby means of an opening 30 at the bottom of the partition.

The cylinder or chamber member 27 is of a height to terminate considerabl short of the lower surface of the bed 10 o the press and supported by the cylinder member and preferably on each side of the partition 29 are tubular members 31 which extend for any desired distance into the respective chambers of the member 27. These tubular members 31 are supported by means of a flange 32 resting upon the top of the member 27 and fastening devices 33 secure the members 31 in position.

A iston 34 is reciprocable in the tubular mem er 31, one for each of the members 31 and encompassing the piston is a packing 35 which engages and rests upon a shoulder 36 on the inner face of the member 31, a packing ring 37 being also provided to co-operate with the shoulder 36 to compress the packing about the piston and thereby form a fluid tight joint. The packin ring 37 is held in position by means of suitab e fastening devices 38.

The pistons 34 serve as supports upon which the pressure pad 21 rests and when the presure pad 21 is at the limit of its upward movement, or in a position to engage the low er face of the bed or bolster plate 12 the upward movement of the pistons 34 will be limited. Likewise, when the pressure pad is depressed by the action of the die 14 on the ram 15, forcing the'blank or Work holder member 19 downwardly as the work 39 is be ing formed over the die 13, the pistons will be forced downwardly into the tubular members 31 and into the respective compartments of the cylinder member 27.

The downward movement of the pistons 34 and also of the pressure pad 21 will be' yieldingly resisted by the compression of the fluid in the compartments of the cylinder member 27. A predetermined amount of fluid is delivered into the cylinder element 27 from any suitable source through a pipe 40, a pressure regulating valve 41 being arranged in the pipe and a pressure indicating gauge 42 also bemg provided\to indicate the amount of ressure in the cushion.

hus it will be manifest that when the parts are in the positon shown in Figures 1 and 2, and a predetermined amount of fluid is supplied to the cylinder member 27 the pressure of the fluid upon the pistons 34 will cause the pistons to rise to the position shown in Figures 1 and 2.

When, however, the pressure pad is lowered the pistons will be forced against the pressure of e fluid in the cylinder element 27 to be yiel ingly resisted thereby.

When the ram starts to ascend the pressure ring 19 will be of the fluid in the cylinder element 27 will operate upon the pistons 34 to'cause them to rise, with the result that the pressure pad 21 and the work holding member or draw returned to their normal positions.

In the form of the invention shown in Fig- I ures 3 and 4, the tubular members 43, correspondin to the tubular members 31, are each provide with a head 44 beneath which a piston 45 is aranged. The piston 45 is provided with suitable packing to form a fluid tight joint and the head 44 is provided with outlet openings 46 therein to permit air above the piston 45 to escape when the piston is raised and to permit air to enter the tubular member 43 above the piston 45 when the latter is lowered to prevent the formation of a vacuum or suction which might be created on the top of the piston 45 to interfere with the operation of the piston.

A supplemental tubular member 47 is secured to the head 44 in alinement with the tubular member 43 and this supplemental tubular member is provided with a head 48 having outlet openings 49 therethrough- A piston 50 is arranged in the supplemental tubular member 47 and operates in unison with the piston 45 through the medium of a piston rod 51 which connects the pistons 45 and 50, suitable packing being provided for the piston 50 to form a fluid tight joint.

The piston rod 51 has communication with the interior of the cylinder member 27 through the end thereof and a port or passage 52 which extends through the piston rod 51 also has communication with the interior of the supplemental tubular member 47 as at 53,

below the piston 50, so that the fluid pres ure in the cylinder member 27 will also be manifested in the supplemental tubular member 47 beneath the piston 50.

The openings 49 are provided to permit air above the piston 50 to escape when the piston rises and .to-permit the entrance of air when the piston descends.

The piston rod 51 extends above the piston 52 and is connected by means of a suitable coupling device 54 with the pressure pad 21, and the piston rod 51 passes through suitable stufling boxes 55-56.

When the parts are in the position shown in Figures 4 and 5, the pressure of the fluid in the cylinder member 27 operating upon the pistons 45 and 50 will cause them to rise thereby returning the pressure pad 51 to its normal position.

\Vhen the pressure pad is depressed during the operation of the press, the pistons 50 and 45 will be lowered against the pressure of the fluid in the cylinder member 27, which latter is also manifested in the tubular member 47 beneath the piston 50. the fluid beneath the piston 50 in .the tubular member 47 passing therefrom through the passage 53-52:

. turn the of a plurality of separate cylinders. Furto the thermore, thedevice may be attached as a single unit to a press and by reason of the construction of the cushioning device the cost of manufacture will be materially reduced and the amount of space necessary to install the device will be reduced to a minimum.

While the preferred forms of the invention have been herein shown and described, it is to be understod that-various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is 1. As a unitary structure a cushioning device for sheet metal drawing presses embodying a single cylinder member, a plurality of pistons separate from each other and operating through'the' same wall of the cylinder,'means for securing the cushioning device ress, means for maintaining a predetermined supply of fluid in said cylinder member to yieldingly resist the movement of the pistons in one direction, additional cylin- 01ers communicatin with the first said cylinder, and additiona? pistons operatively connected with the respective first said pistons and operating in the said additional cyliners.

2. As a unitary structure a cushioning device for sheet metal presses embodying a cylinder member, a plurality ofpairs of superposed cylinders, one cylinder of each pair communicating with the said cylinder member through the same wall of the latter, pistons individual to the said superposed 2 cylinders, the pistons of-each pair being connected for simultaneous reciprocation, means formlng communication betweenthe other cylinder of each of said pairs and the said cylinder member and on one side only of the last said piston, a predetermined supply of fluid in the said cylinder member whereby the pistons will be yieldingly resisted in their "movement in one direction, and means for securing said cushioning device as a unit to the press.

3. A sheet metal press embodylng a forming block, means adapted to grip a sheet,

metal blank, means to move said gripping means and block relatively onewith' relation to the other to shape the blank over the block,

in combination with a freely attachable and detachable fluid pressure cushion acting to yieldingly resist the movement of said gripping means, said cushion embodying as a unitary structure a cylinder, a plurality of piston elements separate from each other and operating through the same side of the cylinder and in the same horizontal plane, means for securing the cushioningdevice in position on a press, and a pressure pad supported by said pistons. I

' 4. A sheet metal press embodying a forming block, means adapted to grip a sheet metal blank, means to move said gripping means and block relatively one with relation to the other to shape the blank over the block in combination with a freely attachable and detachable fluid pressure cushion acting to yieldingly resist the movement of said gripping means, said cushion embodying as a unitary structure a cylinder, a plurality of piston elements separate from each other and operating through the same side of the cylinder and in the same horizontal plane, means for securing the cushioning device in position on a press, said pistons, and means for maintainin a predetermined supply of fluid in said cylin- 5. As a' unitary structure a cushion for sheet metal presses embodying a closed reservoir chamber, means detachably supporting the same below the bed of a press, a plurality of cylinder members open at both ends and extending through the same wall of the reservoir chamber, said cylinder members being of diameters considerably'smaller than the internal diameter of said chamber, pistons operating in the cylinder members, said cylinder andpiston members being one stationary and the other reciprocablewith respect to the other and stationary one, and

a pressure pad supported by the movable one of the piston and'cylinder members.

6. As a unitary structure 'a cushion for sheet metal presses embodying a closed reservoir chamber, means detachably sup- -porting the same below the bed of a press,

one of the piston and cylinder members, said reservoir chamber containing a predetermined amount of fluid for yieldingly resisting the movement of the pad in one direction.

.7. As a unitarystructHre a fluid ressure cushion for sheet metal presses em odying a pressure pad supported by a forming block, blank gripping means, a cylinder and a plston, 'the cylinder and piston movable with relation to each other and actuated by th'eblank gripping means, and a fluid pressure reservoir constituting an integral partof the cylinder, said reservoir being in direct communication with the cylinder.

8. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a forming block, blank gripping means, a cylinder, a piston in the cylinder, thecylinder and piston movable with relation to each and actuated with the blank gripping means, and a fluid pressure reservoir directly at- 1 tached to the-cylinder, said reservoir being in direct communication with the cylinder.

9. As a unitary structure fluid pressure cushions for sheetmetal presses embodying a forming block, blank gripping means, a

plurality of cylinders and pistons, said cylinders and pistons movable with relation to each other and actuated by the blank gr pping means, and fluid pressure reservoirs constituting integral parts of the cylinders, said reservoirs being in direct communication with the cylinders and with each other.

10. As a unitary structure fluid pressure cushions for sheet metal presses embodying a forming block, blank gripping means, a plurality of cylinders and pistons, sa1d cylinders and pistons movable with relation to each other and actuated by the blank gr1p ping means, and fluid pressure reservoirs d1- 'rectly attached to the cylinders, saidrcs ervoirs being in direct communication with the cylinders.

11. As a unitary structure a fluid pressure cushion for sheet metal presses embodylng a forming block, blank gripping means, a. cylinder, a piston in the cylinder, the cylinder and piston movable with relation to each other and actuated with the blank gripping means, a fluid'pressure reservoir directly. attached to the cylinder,- said reservoir being I indirect communication with the cylinder,

and means for supplying said cylinder and piston with fluid pressure from fluid pressure means separated from the fluid pressure cushion.

12. As a unitary structure fluid pressure cushions for sheet metal presses embodying a forming block, blank gripping means, a plurality of cylinders and pistons, said cylinders and pistons movable with relation to each other and actuated by the blank gripping means, fluid pressure reservoirs constituting inte ral. parts of the cylinders, said reservoirs being in direct communication with the cylinders and with each other, and means for sup lying said cylinders and pis tons with fluid pressure from fluid pressure means separated from the fluid pressure cushion.

13. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a forming block, blank gripping means, a plurality of cylinders and pistons, said cylinders and pistons movable with relation to each other and actuated by the blank gri ping means, fluid pressure reservoirs direct y attached to the cylinders, said reservoirs being in direct communication with the cylinders, and means for supplying said cylinders and pistons with fluid pressure from fluid pressure means separated from the fluid pressure cushion.

14. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a a forming block, blank gripping means, a cylinder, a piston in the cylinder, said cylinder and piston movable with relation to each other and actuated by the blank gripping means, a fluid pressurereservoir constituting an integral part of t e cylinder, said reservoir being in direct communication with the cylinder, and means forsupplying said cylinder and piston with fluid pressure from fluid pressure means separated from the fluid pressure cushion.

15. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a cylinder, a piston in the cylinder, the vcylinder and piston movable with relation to -each other and actuated by the blank gripping means, a fluid pressure reservoir constituting an integral .part of the cylinder, said reservoir being in direct communication with the cylinder, and means for attaching or detaching said fluid pressure cushion to said press bed.

16. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a cylinder, a piston in the cylinder, the cylinder and piston movable with relation to each other and actuated with'the blank gripping means, a fluid pressure reservoir directly attached to the cylinder, said reservoir being in direct communication with the cylinder, and means for attaching or detaching said fluid'pressure cushion to said press bed.

17. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a pluralit of cylinders and plstons, said cylinders and pistons movable with relation to each other and actuated by the blank gripping means, fluid pressure reservoirs constituting integral parts of the cylinders, said reservoirs being in direct communication with the cylinders and with each other, and means for attaching or detaching said fluid pressure -cushion to said press bed.

18. As a unitary-structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a plurality of cylinders and pistons, said cylinders and pistons movable with relation to each other and actuated bythe blank gripping means, fluid pressure reservoirs directly attached to the cylinders, said reservoirs being in direct' communication with the cylinders, and means for attaching or detaching said fluid pressure cushionto said press bed.

19. As a unitary structure a fluid pressure cushion for sheet metal presses embod ing a press bed, a forming block, blank gripping means, a cylinder and a piston, the cylinder and piston movable with relation to each 'other and actuated with the blank gripping.

means, a fluid pressure reservoir directly attached to the cylinder, said reservoir being in direct communication with the cylinder, and means for supplying said cylinder and piston with fluid pressure from fluid pressure means separated from the fluid pressure cushion.

20. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a plurality of cylinders and pistons, said cylinders and pistons movable with relation to each other and actuated .by the blank gripping means, fluid pressure reservoirs constituting integral parts of the cylinders, said reservoirs being in direct communication withthe cylinders and with each other, and means for supplying said cylinders and pistons with fluid pressure from fluid pressure means sepa-' rated from the fluid pressure cushion.

21. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a plurali-t of cylinders and'plstons,

said cylinders an pistons movable with relation to each other and actuated by the blank gripping means, fluid pressure reservoirs directly attached to the cylinders,- said reservoirs being in direct communication with the cylinders, and means for sup lying said cylinders and pistons with fluid pressure from fluid pressure means separated from the fluid pressure cushion.

22. As a unitary structure a fluid pressure cushion for sheet metal presses embodying a press bed, a forming block, blank gripping means, a cylinder,.a piston. in the cylmdcr, said cylinder andpiston movable with relation to each other and actuated by the blank gripping means, a fluid pressure reservoir constituting an integral part of the cylinder, said reservoir being in direct communication with the cylinder, and means for supplying said cfylinder and piston with fluid ressure from uid pressure means separated rom the fluid pressure cushion.

In testimony whereof I have signed my name to this specification, on this 11th day of April, A. D, 1929.

- FREDRICH J. RODE.. 

